Balancing the Efficiency and Synthetic Accessibility of Organic Solar Cells with Isomeric Acceptor Engineering

作者：Yang, Qianguang; Chen, Haiyan; Lv, Jie; Huang, Peihao; Han, Deman; Deng, Wanyuan; Sun, Kuan; Kumar, Manish; Chung, Sein; Cho, Kilwon; Hu, Dingqin; Dong, Haiyan; Shao, Li; Zhao, Fuqing; Xiao, Zeyun^*; Kan, Zhipeng^*; Lu, Shirong^*

来源：Advanced Science, 2023, 10(20).

DOI：10.1002/advs.202207678

• organic solar cell
• small-molecule acceptor
• isomeric engineering
• synthetic simplification
• cost-effectiveness

With the continuous development of organic semiconductor materials and on-going improvement of device technology, the power conversion efficiencies (PCEs) of organic solar cells (OSCs) have surpassed the threshold of 19%. Now, the low production cost of organic photovoltaic materials and devices have become an imperative demand for its practical application and future commercialization. Herein, the feasibility of simplified synthesis for cost-effective small-molecule acceptors via end-cap isomeric engineering is demonstrated, and two constitutional isomers, BTP-m-4Cl and BTP-o-4Cl, are synthesized and compared in parallel. These two non-fullerene acceptors (NFAs) have very similar optoelectronic properties but nonuniform morphological and crystallographic characteristics. Consequently, the OSCs composed of PM6:BTP-m-4Cl realize PCE of 17.2%, higher than that of the OSCs with PM6:BTP-o-4Cl (approximate to 16%). When ternary OSCs are fabricated with PM6:BTP-m-4Cl:BTP-o-4Cl, the averaged PCE value reaches 17.95%, presenting outstanding photovoltaic performance. Most excitingly, the figure of merit (FOM) values of PM6:BTP-m-4Cl, PM6:BTP-o-4Cl, and PM6:BTP-m-4Cl:BTP-o-4Cl based devices are 0.190, 0.178, and 0.202 respectively. The FOM values of these systems are all among the top ones of the current high-efficiency OSC systems, revealing high cost-effectiveness of the two NFAs. This work provides a general but accessible strategy to minimize the efficiency-cost gap and promises the economic prospects of OSCs.

• 单位
  广西大学; 中国科学院研究生院; 重庆大学